1. Field of the Invention
The present disclosure relates to shuttle vectors for Mycobacteria and Escherichia coli and their use.
2. Description of the Related Art
For the expression of heterologous proteins in eukaryotic cells, the transgene is usually introduced through a process called bactofection using viruses or bacteria as delivery systems. Consequently bacteria harboring protein encoding plasmids enter a eukaryotic cell and release the plasmid for uptake into the nucleus, where the plasmid encoded genes are expressed endogenously, and the plasmid may be either stably integrated into the genome of the cell or be present in the cytoplasm without being integrated into the genome. Particularly, Mycobacteria can be used advantageously as a delivery system for inducing/enhancing an immune response to proteins encoded in the plasmid because of its ability of disrupting immune tolerance in host at the cytotoxic T-level. At present, pAL5000 replicon is the most widely used vector as a Mycobacteria-Escherichia coli shuttle plasmid for a variety of uses. However the system has some drawbacks that the protein expressed from the vector in mycobacteria is not correctly folded and modified. Therefore there are demands for the new vector system which can correctly and reliably produce the encoded proteins.